• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.77-81
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• 1999

The predictions of metal flow forging load optimal die angle and preform size are not so easy in turbine blade forging. First of all the quality of final product is influenced by side force which is one of the significant factors. in this study slab method is applied to determine optimal die angle minimizing side force and the position of preform Finally drawing of die design is obtained in optimal die angle with developing tool that is composed of Visual Basic.

• 대한토목학회논문집
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• 제33권2호
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• pp.455-464
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• 2013

남북한이 상이한 사회적 규범체계 하에 분단국가로 장기화될수록, 건설기술에 대한 이론적 기술적 차이가 많이 발생하게 된다. 따라서 남북한이 화해의 국면에서 상호 교류시, 공동으로 사용하는 철근콘크리트 도로교의 성능수준도 명확히 차이가 발생한다. 이에 본 연구는 북한의 철근콘크리트 도로교 설계기준과 관련된 자료를 면밀히 비교 분석하고, 철근콘크리트 슬래브교에 대한 표준설계 제원과 사례를 토대로 구조해석을 수행했다. 특히 남북한의 설계트럭하중에 대하여 활하중 영향을 분석함으로써, 북한의 철근콘크리트 슬래브교에 대한 수준을 추정하였고, 이를통해 통행에 대한 안전성을 사전에 검토할 수 있도록 기초 연구를 수행하였다. 따라서 향후 남북한이 화해국면에 접어들어 교류가 활발히 진행되거나, 더 나아가 통일국가로 준비하는 단계에서, 공통의 철근콘크리트 도로교 설계기준을 작성하는데 기초자료로 활용될 것으로 기대한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.400-405
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• 2011

The total length of Korean urban railways reaches 1,200km. Urban railway used to be installed with ballasted tracks by reason of low cost at the time of construction, slab tracks are now being installed due to the reasons of the improvement in safety, lengthening service life and more economical method in terms of maintenance. The length rate of slab tracks has exceeded 70% of the domestic urban railways with the methods ranging from STEDEF, LVT, ALT, Eidan-type, B2S to RHEDA. This study surveyed the share of domestic slab tracks, and compared and evaluated the input cost at the initial stage by the types of slab tracks. Construction processes have been standardized by the existing design documents and calculated the initial input cost for the length of 1km of a hypothetical straight line. Cost breakdown structure was evaluated as materials cost, construction cost, equipment cost, indirect cost, etc. It is expected that this study will be used in selection & evaluation which is considering the economic feasibility of slab tracks.

• 대한토목학회논문집
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• 제14권3호
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• pp.473-485
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• 1994

정말진동환경을 요구하는 혐진기기 하부의 콘크리트슬래브를 대상으로 하여 시간영역에서만이 아니라 진동수영역에서의 진동수준을 허용진동범위 이하로 제어하므로써 요구되는 진동환경을 조성하는데 본 연구의 목적이 있다. 이를 위하여 콘크리트슬래브에 대한 진동실험을 실시하여 진동수영역에서의 동적응답 및 가진점과 응답점간의 진동수응답함수를 구한다. 또한 실험적모드해석법에 의하여 콘크리트슬래브의 동특성을 분석한다. 이를 근거로 외부로부터의 가진진동수와 콘크리트슬래브의 고유진동수간의 공진현상을 피하기 위하여 계의 동특성을 변경하므로써 구조물의 동적응답을 제어할 수 있다.

• Structural Engineering and Mechanics
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• 제43권4호
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• pp.459-473
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• 2012

Post-tensioned concrete voided slab girders are widely used in highway bridge constructions. To obtain greater section hollow rate and reduce the self-weight, the plate thickness of slab girders are designed to be small with the adoption of flat anchorage system. Since large prestress is applied to the anchor end section, it was found that longitudinal shear cracks are easy to occur along the voided slab girder. The reason is the existence of great shearing effect at the junction area between web and bottom (top) plate in the anchor end section. This paper focuses on the longitudinal anti-cracking problem at the anchor end of post-tensioned concrete voided slab girders. Two possible models for longitudinal anticracking analysis are proposed. Differential element analysis method is adopted to derive the solving formula of the critical cracking state, and then the practical analysis method for longitudinal anti-cracking is established. The influence of some factors on the longitudinal anti-cracking ability is studied. Results show that the section dimensions (thickness of bottom, web and top plate) and prestress eccentricity on web plate are the main factors that influence the anti-cracking ability. Moreover, the proposed method is applied into three engineering examples to make longitudinal anti-cracking verification for the girders. According to the verification results, the design improvements for these girders are determined.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.282-291
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• 2010

In line with current speed-up of railroad, a slab track has been increasingly adopted in a bid to secure the safety of track structure as well as to reduce the maintenance cost, and furthermore, the need for commercialization of domestically-developed swing-nose crossing turnout on slab track has been on the rise. For commercialization of swing-nose crossing turnout on slab which was developed in Korea, a technical and systematic performance evaluation system, considering local environment, shall be established and then the performance evaluation shall be accordingly implemented. This paper was intended to summarize the performance evaluation system, referring to the data available at home and abroad and the results of performance evaluation for domestically-developed swing-nose crossing turnout on slab track carried out to date based on that system. A performance evaluation system comprises the technical requirement appropriateness evaluation(component performance evaluation and design verification), laboratory test and on-site test. For domestically-developed swing-nose crossing turnout on slab track, appropriateness evaluation and laboratory test have been completed and the on-site test of those installed on the 2nd phase of Kyung-Bu HSR is underway now.

• 대한건축학회논문집:구조계
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• 제35권10호
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• pp.163-170
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• 2019

In spite of various advantages, steel fiber reinforced concrete is still limited in its use due to the insufficient research results on the structural performance and design criteria. This study evaluated the long-term behavior of the steel fiber reinforced concrete slabs by long-term loading experiments based on the short-term load bearing capacity of steel fiber reinforced concrete slabs obtained from previous studies. In this study, long-term loading experiments were carried out on Total four 2-span continuous slab specimens were tested for examining the long-term behavior of steel fiber reinforced concrete members. Long-term behavior characteristics of members were evaluated by measuring the long-term deflection, drying shrinkage, the number and width of cracks. Experimental results showed that the instant deflection of the steel fiber reinforced concrete slab is about 50% of the normal reinforced concrete slab. And, it was analyzed that the long-term deflection of the specimen using steel fiber reinforced concrete was about 10~20% lower than that of normal concrete by the long-term deflection over 100 days. In addition, the slab specimen using steel fiber reinforced concrete was evaluated to have just 70% of the number and width of cracks compared with normal concrete specimens.

• 한국공간구조학회논문집
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• 제23권2호
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• pp.61-68
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• 2023

A two-hour fire-resistance PC hollow slab for residential use was developed to secure structural and fire-resistance performance and to be applied to the general building and apartment housing markets. Compared to the existing hollow slab, in order to secure the same or better structural performance and economic feasibility by reducing the quantity, it was attempted to secure the fire resistance performance by reducing the concrete filling rate in the cross section and adjusting the thickness of the upper and lower flanges by optimizing the hollow shape in the cross section of the slab. For structural performance evaluation, experiments were performed on PC hollow slabs by varying the member thickness and the presence or absence of overlaid concrete, and all of the experimental results showed that the design strength was sufficiently exhibited and that stability during construction was possible. The developed synthetic PC hollow slab has secured fire resistance and residential performance so that it can be applied to all buildings, and it is intended to be immediately applied to the field.

• 한국안전학회지
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• 제28권5호
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• pp.41-48
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• 2013

This paper is intended to provide the background information and justification for Korean highway bridge design code(limit state design)(2012). Limit state design method calculates reliability index and probability of failure through the analysis of the reliability of the experimental database. It has become possible to perform the economical and consistent design by evaluating the safety of a structure quantitatively. In this paper, we used the design specifications of RC slab bridge of superstructure form of Road Design Manual in Part 5 bridge built in highway bridge. This study conducted structural analysis using the method of frame structure theory, design and analysis of bridge by limit state design method, the design code including various standards and Load model applied Korean highway bridge design code limit state design(KHBDC;2012). As a result, it analyzed the effect of safety through comparison. Showing effect of improvement the safety factor and comparing the value of the result, it is determined to be capable of economical design and safety. Furthermore, limit state design method was able to determine many redundant force of cross-section compared with existing design method. It is determined that it can reduce the overall amount because of the reduction of the cross-section and girder depth.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.681-686
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• 2001

The purpose of this study is to provide the optimum mix design of concrete to be placed at the face slab concrete in CFRD(Concrete Faced Rockfill Dam) for pumped storage power plants. The basic performance tests including compressive strength, modulus of elasticity, flexural strength and the control properties of crack including plastic shrinkage, drying shrinkage were conducted for concrete using fly ash and polypropylene fiber. From this study, the fly ash concrete represented the better results in the aspects of basic performance, control properties of crack and economy than ordinary portland cement concrete. Especially the concrete mix design containing 20% of fly ash is recommended to be applied in the construction of the face slab concrete in CFRD for pumped storage power plants.